More publicly acceptable and FCC-friendly version of S.T.F.U., originally coined by Buckethead on WJRR Radio.

A phrase used not as a substitute for 'Shut the fuck up', but rather when the front door requires shutting.

Politically correct way of saying, Shut the fuck up when at work or in front of parents etc

Shut the f* up
Are you serious?
When someone states the obvious.

This is the phrase you say when you are in front of young people, old people, and your boss. Or if you just don't want to cuss. It is a lot better than saying "What the fuck!?" Or "Shut your mouth!". It is a censor phrase and is commonly used by Stacey London on What Not to Wear.

something you say to not swear or nearly did swear

A most useful expression for shut the f**k up. Used when in annoyance, frustration, anger, etc.